FN-DSA for JOSE and COSE

This document specifies JSON Object Signing and Encryption (JOSE) and CBOR Object Signing and Encryption (COSE) serializations for FFT (fast-Fourier transform) over NTRU-Lattice-Based Digital Signature Algorithm (FN-DSA), a Post-Quantum Cryptography (PQC) digital signature scheme defined in US NIST FIPS 206 (expected to be published in late 2026 early 2027). It does not define new cryptographic primitives; rather, it specifies how existing FN-DSA mechanisms are serialized for use in JOSE and COSE. This document registers signature algorithms for JOSE and COSE, specifically FN-DSA-512 and FN-DSA-1024.